From: Paulo Alcantara <pc@manguebit.com>
Date: Mon, 11 Dec 2023 10:26:40 -0300
Subject: [PATCH] smb: client: fix OOB in receive_encrypted_standard()
Git-commit: eec04ea119691e65227a97ce53c0da6b9b74b0b7
References: bsc#1218832 CVE-2024-0565
Patch-mainline: v6.7-rc6
Fix potential OOB in receive_encrypted_standard() if server returned a
large shdr->NextCommand that would end up writing off the end of
@next_buffer.
Fixes: b24df3e30cbf ("cifs: update receive_encrypted_standard to handle compounded responses")
Cc: stable@vger.kernel.org
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
fs/smb/client/smb2ops.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index fcfb6566b899..a6f4948adcbb 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -4943,6 +4943,7 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
struct smb2_hdr *shdr;
unsigned int pdu_length = server->pdu_size;
unsigned int buf_size;
+ unsigned int next_cmd;
struct mid_q_entry *mid_entry;
int next_is_large;
char *next_buffer = NULL;
@@ -4971,14 +4972,15 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
next_is_large = server->large_buf;
one_more:
shdr = (struct smb2_hdr *)buf;
- if (shdr->NextCommand) {
+ next_cmd = le32_to_cpu(shdr->NextCommand);
+ if (next_cmd) {
+ if (WARN_ON_ONCE(next_cmd > pdu_length))
+ return -1;
if (next_is_large)
next_buffer = (char *)cifs_buf_get();
else
next_buffer = (char *)cifs_small_buf_get();
- memcpy(next_buffer,
- buf + le32_to_cpu(shdr->NextCommand),
- pdu_length - le32_to_cpu(shdr->NextCommand));
+ memcpy(next_buffer, buf + next_cmd, pdu_length - next_cmd);
}
mid_entry = smb2_find_mid(server, buf);
@@ -5002,8 +5004,8 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
else
ret = cifs_handle_standard(server, mid_entry);
- if (ret == 0 && shdr->NextCommand) {
- pdu_length -= le32_to_cpu(shdr->NextCommand);
+ if (ret == 0 && next_cmd) {
+ pdu_length -= next_cmd;
server->large_buf = next_is_large;
if (next_is_large)
server->bigbuf = buf = next_buffer;
--
2.35.3